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PubMed1979

[Changes in enzymes during aging of human diploid cells. Glucose-6-phosphate dehydrogenase].

The thermal inactivation kinetics of glucose-6-phosphate dehydrogenase during ageing of human diploid cells were studied. It was shown that semi-logarithmic anamorphisms of the thermal inactivation kinetic curves may be presented as a total of two rectilinear sites corresponding to the thermolabile and thermostable fractions of the enzyme. In ageing cells the enzyme stability is decreased as compared to the young ones due to the increase in the amount of the thermolabile fraction. It was also found that despite a certain variability in the process of the cell growth at the 22nd passage the thermal stability of glucose-6-phosphate dehydrogenase is decreased, while the enzyme thermal stability in the cells at the 52nd passage is monotonously increased. Purification of the enzyme from ageing and young human diploid cells results in an increase of the enzyme stability. However, when the enzyme was isolated from young cells, it possessed a higher thermal stability.

Cell Line↗

PubMed1983

[Increase in cell metabolism in normal, diploid human glial cells in stationary cell cultures induced by meclofenoxate].

Quantitative biochemical studies were undertaken in order to examine the influence of the accumulation of lipofuscin in secondary lysosomes on cell metabolic activities of normal diploid human glia cells in a stationary cell culture system. Glia cells accumulate lipofuscin as a function of the duration of the stationary cultivation in vitro. The accumulation of lipofuscin can be decreased by the long-term treatment with the pharmacon meclofenoxate (centrophenoxine, Helfergin). Concomitant with the reduction of the accumulated lipofuscin, meclofenoxate-treated glia cells show enhanced rates of RNA synthesis, protein synthesis and glucose uptake. Most likely, in meclofenoxate-treated normal diploid human glia cells in vitro, the utilisation of glucose is shifted from glycolysis to the pentose phosphate pathway. The data suggest that the meclofenoxate-induced reduction of lipofuscin accumulation has a positive effect on cell metabolic functions and causes a delay of the cellular aging of the human glia cells in vitro.

Diploidy↗

PubMed1981

Diploid-triploid mixoploidy: clinical and cytogenetic aspects.

A patient with 46, XY/69,XXY mixoploidy (a mixture of cell populations whose component cells differ in their chromosome numbers, irrespective of whether these numbers are euploid or aneuploid) who had some clinical manifestations of the Russell-Silver syndrome is reported. Triploidy results in a clinically recognizable lethal syndrome with hydatidiform placental changes, severe intrauterine growth deficiency, dysplastic cranial bones, eye defects, cleft lip and/or, palate malformed ears, micrognathia, syndactyly, genital anomalies and, rarely, spina bifida. Less severe are instances of diploid-triploid mixoploidy and patients are more likely to survive; one of these patients was detected at birth because of asymmetric growth deficiency with syndactyly. Cytogenetic and flow cytometric studies demonstrated absence of triploid cells in peripheral lymphocytes while varying proportions of triploid cells were found in fibroblast cultures derived from each limb. The triploid cell population disappeared with prolonged cell culture. Replication studies with 5-bromodeoxyuridine-DAPI fluorescence revealed two active X chromosomes, and marker chromosomes suggested a paternal origin for the extra haploid set. The following points are emphasized: (1) diploid-triploid mixoploidy can be suspected clinically; (2) the triploid cell population may not be detectable on examination of peripheral blood (3) the relative degree of asymmetry in the growth deficiency does not appear to relate to the proportion of triploid cells; and (4) both X chromosomes may remain active in the presence of an extra haploid set of chromosomes.

Abnormalities, Multiple↗

PubMed1981

Representation of mRNA sequences in normal and SV40 transformed human diploid fibroblasts.

The representation of mRNA sequences in normal and SV40-transformed WI-38 human diploid fibroblasts was examined. Variations in the hybridization of polysomal RNAs to 3H-labeled DNAs complementary to poly A+ mRNA of normal and SV40-transformed cells suggest differences in the mRNA populations. a comparison of the representation of histone RNA sequences of normal and SV40-transformed human diploid cells did not reveal significant differences.

Base Sequence↗

PubMedDate not supplied

[Hexokinase and sucrose phosphorylase activity of cell-free preparations of haploid and diploid strains of Pullularia pullulans].

The autodiploid strain of Pullularia pullulans 1125(4)(13) that differs from the haploid strain 1125(4) in the rate of synthesis of the polysaccharide pullulan has a higher activity of hexokinase in cell-free preparations. A change in the activity of hexokinase in the diploid strain coincides in time with a change in the rate of the polysaccharide synthesis: the activity of hexokinase in cell-free preparations is highest when the rate of pullulan synthesis is maximal. In the haploid strain, the activity of hexokinase in preparations from the cultures grown for 24, 38 and 48 hours remains at the same level, and then decreases by the 72nd hour. The activity of sucrose phosphorylase in cell-free preparations of the haploid strain increases with aging of the culture; in preparations of the diploid strain, the activity decreases by the 38th hour and then increases like in the haploid strain. These data make it possible to suggest that the activity of hexokinase, rather than that of sucrose phosphorylase, influences the rate of pullulan synthesis.

Cell-Free System↗

PubMed1984

[Variability of alkaline phosphatase activity in diploid human cells in vitro].

Experiments were made with 19 strains obtained from different tissues (skin, lungs, muscles) of 8-10-week-old medical abortions and skin biopsies of healthy donors to study the manifestations of alkaline phosphatase (AP) activity in human diploid cells in vitro. Based on the data obtained it is concluded that AP activity is marked by demonstrable intra- and interstrain variability. The spectrum of "AP activity" trait variability is broader for transformed cells than for human diploid cells.

Adult↗

PubMed1984

Alteration of ceramide monohexoside in human diploid fetal lung fibroblasts during cell aging.

Serially cultured human diploid fibroblasts have a finite lifetime in vitro, and this phenomenon was postulated as cellular aging. Neutral glycosphingolipids (GSLs) from human fetal lung-derived diploid fibroblast cell lines, WI-38 and TIG-1 cells, were studied during cellular aging. Both cell lines had at least four types of neutral GSLs. It was found that neutral GSLs changed with aging, the most conspicuous alteration being a 2-4-fold increase in the content of ceramide monohexoside. This change was invariably observed in either WI-38 or TIG-1 cells.

Cell Line↗

PubMed1980

[Formation of stable diploid bacteria by fusion of protoplasts of Bacillus subtilis and the effect of rec- mutations on the fusion products formed].

A minority among the prototrophic clones formed when protoplasts from two polyauxotrophic strains of B. subtilis are fused has been shown to be diploid, carrying the parental deficient alleles in their DNA, and generally segregating auxotrophs when grown in nutrient medium. This is true whether the strains being fused are Rec+ or Rec-, since the rec- mutations used hardly affect recombinations occurring between chromosomes in diploid Bacteria.

Alleles↗

PubMed1978

Human rabies globulin and human diploid vaccine dose determinations.

Veterinary students were injected with either human rabies immune globulin and human diploid rabies vaccine, or with human diploid vaccine alone. All those students who received three or more doses of the vaccine developed high levels of neutralizing antibodies by the rapid fluorescent focus inhibition test (RFFIT). The levels of early antibody in the students receiving the combination of globulin and vaccine depended very much on the dose of globulin. The neutralizing antibody levels in the sera of students who received 12 IU/kg were low 48 hours after the globulin injection: 6 of the 25 students receiving this dose were found to have no antibody, and eight were found to have titers between 1:6 and 1:10. When the globulin dose of 20 or 30 IU/kg was administered all students had early titers of 1:11 or above and all students subsequently developed high levels of antibody.

Adult↗

PubMed1983

Characteristics of human diploid fibroblasts transformed in vitro by chemical carcinogens.

We investigated several potential methods to select for carcinogen-induced changes in N-acetoxy-2-acetylaminofluorene-treated normal human diploid fibroblasts, in an effort to isolate cells exhibiting the transformed phenotype. Treated cultures exhibited an extended but not indefinite life span, as well as an increased cloning efficiency in reduced calcium concentrations at 40 to 50 population doublings posttreatment. Morphologically altered foci in monolayer culture, the capacity to proliferate under reduced serum or calcium concentrations, or the ability to grow on irradiated 3T3 monolayers did not uniquely identify or select for a carcinogen-induced phenotype. Treated cultures did routinely produce viable colonies when assayed under anchorage-independent (AI) conditions. This AI phenotype persisted for at least 2 months; when cells from such colonies were isolated and retested, a 2-fold enhancement in the frequency of AI growth was observed. AI-derived cells showed no stable morphological alteration in monolayer culture as regards either growth pattern or cytology. Four out of 10 strains of cells derived from AI colonies and grown to sufficient numbers in monolayer for tumorigenicity testing produced tumors in nude mice; only one of these was invasive and grew progressively to greater than 1 cm in diameter. Cells recovered from these tumors were diploid and of fibroblastic morphology. The AI phenotype appears to be an early marker for a carcinogen-induced change in human fibroblasts, but it is not systematically associated with the other phenotypic characteristics of transformation usually found concomitantly in rodent cell systems.

2-Acetylaminofluorene↗

PubMed1983

Suppression of tumorigenicity in hybrids of tumorigenic Chinese hamster cells and diploid mouse fibroblasts: dependence on the presence of at least three different mouse chromosomes and independence of hamster genome dosage.

Somatic cell hybrids were generated between Chinese hamster cell lines (Cl-4 and TK 17-O) with a near-diploid number of partially abnormal chromosomes and embryonic mouse fibroblasts (BALB/c). Hybrids harboring a near-diploid, near-triploid, and near-tetraploid set of hamster chromosomes plus 22 to 30 mouse chromosomes were analyzed for the expression of the transformed or tumorigenic phenotype, respectively, indicated by their capacity to form colonies in soft agar and by tumor formation after s.c. injection into nude mice. The hybrids showed (partial) suppression of tumorigenicity and of anchorage independence. The minimum number of hybrid cells required to initiate tumor growth in nude mice was 100- to 50,000-fold higher, and the latency period was 3- to 6-fold longer in comparison with the highly tumorigenic parental hamster cells. Suppression of tumorigenicity was also found in intraspecific Chinese hamster hybrids involving tumorigenic cells (E 36-O and TK 17-O) and embryonic hamster fibroblasts. To identify those mouse chromosomes associated with suppression of tumorigenicity, we investigated the expression of mouse isozyme genes and the presence of mouse chromosomes in interspecific suppressed hybrids and their tumorigenic hybrids described previously. No single mouse chromosome, even if present in two copies, and no combination of two different mouse chromosomes was sufficient to suppress tumorigenicity in these hybrids. This conclusion is based on either the presence of these chromosomes in hybrids isolated from tumors or their absence in suppressed hybrids.

Agar↗

PubMed1982

Preimplantation development of gynogenetic diploid mouse embryos.

Diploid gynogenetic mouse embryos were produced in a three-step procedure: fertilization in vitro, suppression of the 2nd polar body formation by Cytochalasin B, and microsurgical removal of the male pronucleus. The operated eggs were transplanted to the oviduct of recipient females for 72 or 96 h. The overall recovery rate was 73%, but compacted morulae and blastocysts constituted only 28.6% of transplanted eggs. After 72 h blastocysts were rare (3.5%) but 24 h later their incidence increased to 21.2%. In eggs homozygous for T6 chromosome it was possible to prove karyologically that the male pronucleus was effectively removed and that the diploid genome was of purely maternal origin.

Animals↗

PubMed1982

Rhesus diploid rabies vaccine (adsorbed), a new rabies vaccine. Results of initial clinical studies of preexposure vaccination.

To meet the need for a safe, efficacious, and low-cost rabies vaccination program, the Michigan Department of Public Health developed a new rabies vaccine: rhesus diploid rabies vaccine, adsorbed (RDRV). Initial clinical studies were conducted in 534 volunteers using preexposure protocols consisting of two injections of RDRV given 1, 2, or 4 weeks apart. This new rabies vaccine induced an excellent rabies virus antibody response two to three weeks after vaccination: antibody levels were superior to those reported after duck embryo rabies vaccine and were similar to those reported with human diploid rabies vaccine. In addition, vaccination with RDRV was associated with an acceptable level of local and constitutional symptoms.

Adolescent↗

PubMed1982

Intradermal use of human diploid cell vaccine for preexposure rabies immunizations.

In a study involving 240 faculty, students, and staff at the University of Georgia College of Veterinary Medicine, 0.1 ml of a rabies human diploid cell vaccine administered intradermally on days 0, 7, and 28 induced adequate rabies antibody (greater than or equal to 0.5 IU/ml of serum) in all subjects by day 49. There were no significant differences in mean titers between groups of individuals with different rabies immunization histories by using a newly proposed index system for reporting such titers. It was shown that if there was a titer on the day the initial dose was given, it had no bearing on the titer 49 days later. Less than 1% of all the injections resulted in severe reactions, ie, muscular pain, headache, or pain at the site of injection. It was concluded that intradermal use of a low dose of rabies human diploid cell vaccine will induce adequate antibody titers in persons at risk to rabies.

Adult↗

PubMed1980

Isolation of haploid clones bearing a mating allele from a diploid apomictic isolate of Didymium iridis.

Clones of myxamoebae which fail to undergo a direct morphogenetic change into plasmodia have been isolated from cultures of the Philippine-1 isolates of Didymium iridis. These clones have been maintained continuously for a period of more than 4 years without producing plasmodia. It has been demonstrated by Feulgen-DNA cytophotometry that the mean nuclear DNA content of such clones is equivalent to the haploid replicated (2C) value. Conversely, myxamoebae which produce plasmodia directly have a mean nuclear DNA content which is equivalent to the diploid replicated (4C) value. The haploid Philippine-1 clones have been demonstrated to be cross compatible with isolates bearing the mating alleles A1, and A3 through A11, and incompatible with isolates bearing the mating allele A2. Furthermore, plasmodia which result from the crosses Ph-1n (A2) Hon 1-2 (A1), (A1), Ph-1n (A2) x Pan 2-4 (A7) and Ph-1n (A2) x Pan 2-7 (A8) have mean nuclear DNA values which are equivalent to the replicated diploid value, and produce spores which bear the mating alleles in the predicted ratios. Such data demonstrate that the Ph-1n clones are sexually compatible with haploid myxamoebae of heterothallic isolates. The significance of the isolation of these haploid clones with regard to a recent hypothesis related to the evolution of developmental systems in the Myxomycetes is discussed.

Alleles↗

PubMed1981

Booster effect of human diploid cell antirabies vaccine in previously treated persons.

Contact was maintained with 27 of 45 persons for four years after their severe exposure to rabies virus and successful protection. During that time, these persons showed no adverse effects of treatment and maintained rabies-neutralizing antibody at the level of 2 to 91 IU/mL of serum. After a single booster inoculation of human diploid cell culture vaccine four years after the initial treatment, levels of neutralizing antibodies rose to 36 to 650 IU/mL of serum ten days after the booster inoculation. These observations confirm the persistence of rabies-specific serum antibodies for an extended (four years) period after vaccination. Furthermore, a single booster inoculation with human diploid cell culture vaccine resulted in a sharp increase in the level of antibodies, indicating that a person would probably be protected against a second exposure.

Adolescent↗

PubMed1980

Preimplantation development of microsurgically obtained haploid and homozygous diploid mouse embryos and effects of pretreatment with Cytochalasin B on enucleated eggs.

Haploid embryos were obtained by microsurgical removal of one pronucleus, followed by doubling of the haploid chromosome set with Cytochalasin B (CB), either at the first or second mitosis. This procedure provides a source of fully homozygous diploid embryos which were grown in vitro or in vivo. The effect of CB treatment before and during operation on the course of enucleation and further development of embryos was studied. Out of 81 eggs made diploid at 2-cell stage and transplanted into the oviducts of immature or pseudopregnant recipients 27 morulae and blastocysts were recovered, but not a single case of implantation occurred by the eighth or ninth day of development. After 72-80 h of in vitro culture, most of the homozygous embryos were morulae but after an additional 24 h the majority of them transformed into blastocysts. The rate of development of homozygotes was markedly better than that of haploids, which progressed beyond morula stage. The immediate survival rate of operated eggs was dependent on whether or not the eggs were pre-incubated and the enucleation was performed in the presence of CB. In the former case the immediate survival rate was nearly twice as high as in the absence of CB, but more of the treated eggs underwent fragmentation and early developmental arrest.

Animals↗

PubMed1981

Spontaneous neoplastic transformation in vitro of a diploid clone of rat liver cells under conditions of large inoculum size of cells at the transfer.

Attempts were made to examine the correlation of the chromosomal stability and neoplastic transformation with routine subculturing at small and large inoculum sizes of cells. A diploid clone of rat liver cell, Ac7E, was put on a rigid transfer schedule, being transferred every 10 days, and inoculated always at the same cell density or the same split ration. The cells which were subcultured before confluency did not undergo spontaneous neoplastic transformation and maintained diploid karyotype for at least 117 generations (356 culture days) after cloning. However, transformation occurred when cells were transferred for more than 49 generations (265 days) after cloning at a large inoculum size of cells and maintained in the confluent state for a while before subculturing. The transformed cells showed the high saturation density and a multilayered growth pattern in culture. G-band analysis of chromosomes demonstrated the preferential involvement of a complete or partial trisomy of #1 chromosome in a transformed cell line, also in cell lines which were reestablished from induced tumors by the backtransplantation of transformed cells.

Animals↗